Preformed stylet for guiding a lead to contact the septum

Abstract

Preformed guiding stylet for introducing a septal lead in contact with the septum or other intra-corporal device in contact with body tissue. This stylet includes a flexible wire to be introduced by its distal end in a central lumen of the lead, and a control handle. The wire is elastically deformable in bending and has sufficient rigidity in torsion to enable transmission by the handle rotation of a rotational movement over the entire length of the wire. Unstressed, the wire comprises successively in its distal part a first curvilinear portion a first straight portion a second curvilinear portion and optionally a second straight portion. The first and second curvilinear portions extend in respective planes making an angle between them defining a dihedral which axis comprises the first straight portion. The total length of the first curvilinear portion coincides with the anatomical curvature of the venous system.

I claim: 
     
       1. A guiding stylet, for introducing a septal lead to contact an atrial or ventricular septum wall, comprising:
 a flexible wire having a proximal end and a distal end suitable for passage in a central lumen of said septal lead, and 
 a control handle fixed to the proximal end of the wire and rotatable about an axis; 
 said wire being elastically deformable in bending and having in an unstressed state, at its distal end, an unstressed shape comprising, successively: a first curvilinear portion, a first straight portion, and a second curvilinear portion nearer to the distal end of the wire than the first curvilinear portion; 
 wherein the wire has a rigidity in torsion to allow transmission along its length of a rotational movement by a rotation of the handle, whereby the rotational movement of the wire by a rotation of the handle causes an adjustment of an opening angle of the second curvilinear portion by accumulating torque in the wire; 
 wherein the first curvilinear portion and the second curvilinear portion extend in respective planes that make an angle between them that define a dihedral angle that includes the first straight portion, wherein the dihedral angle is less than 45°; 
 wherein the total length of the first curvilinear portion, the first straight portion, and the second curvilinear portion is between 82 and 195 mm; 
 wherein said distal end is configured to be positioned within an anatomical curvature of a venous system extending from a right or left cephalic vein, through a superior vena cava, and towards the septum wall; 
 wherein the distal end comprises a positioned shape when positioned within the anatomical curvature; and 
 wherein the positioned shape substantially matches the unstressed shape. 
 
     
     
       2. The stylet of  claim 1 , wherein the first curvilinear portion and the second curvilinear portion are configured in relation to one another and the first straight portion to extend away from each other on opposite sides of a half plane containing the first straight portion, said stylet being designated to be introduced into the venous system via the right cephalic vein. 
     
     
       3. The stylet of  claim 2 , wherein the control handle further comprises a marking indicating that said stylet is designated to be introduced inside the venous system via the right cephalic vein. 
     
     
       4. The stylet of  claim 1 , wherein the first curvilinear portion and the second curvilinear portion are configured in relation to another and the first straight portion to extend in mutual alignment on the same side of a half-plane containing the first straight portion said stylet being designated to be introduced into the venous system via the left cephalic vein. 
     
     
       5. The stylet of  claim 4 , wherein the control handle further comprises a marking indicating that said stylet is designated to be introduced inside the venous system via the left cephalic vein. 
     
     
       6. The stylet of  claim 1 , wherein the wire further comprises a second straight portion positioned distal of the second curvilinear portion. 
     
     
       7. The stylet of  claim 6 , wherein the second straight portion further comprises a length less than or equal to 15 mm. 
     
     
       8. The stylet of  claim 1 , wherein the dihedral angle is between 10° and 30°. 
     
     
       9. The stylet of  claim 1 , wherein the first curvilinear portion has a radius of curvature less than or equal to 200 mm. 
     
     
       10. The stylet of  claim 9 , wherein the first curvilinear portion has a radius of curvature between 40 and 60 mm. 
     
     
       11. The stylet of  claim 1 , wherein the first curvilinear portion provides an opening angle of at least 10°. 
     
     
       12. The stylet of  claim 11 , wherein the first curvilinear portion provides an opening angle of between 70° and 110°. 
     
     
       13. The stylet of  claim 1 , wherein the first straight portion has a length of at least 10 mm. 
     
     
       14. The stylet of  claim 13 , wherein the first straight portion has a length between 30 and 70 mm. 
     
     
       15. The stylet of  claim 1 , wherein the second curvilinear portion has a radius of curvature between 10 and 15 mm. 
     
     
       16. The stylet of  claim 1 , wherein the opening angle is adjustable between 20° and 40°. 
     
     
       17. A kit for the introduction into the venous system, and for the direction and guidance of the distal end of a probe until contact with the wall of the atrial or ventricular septum, comprising:
 a preformed guiding stylet according to the configuration of  claim 1 . 
 
     
     
       18. A guiding stylet, for introducing a septal lead to contact an atrial or ventricular septum wall, comprising:
 a flexible wire having a proximal end and a distal end suitable for passage in a central lumen of said septal lead, and 
 a control handle fixed to the proximal end of the wire and rotatable about an axis; 
 said wire being elastically deformable in bending and having in an unstressed state, at its distal end, an unstressed shape comprising, successively: a first curvilinear portion, a first straight portion, and a second curvilinear portion nearer to the distal end of the wire than the first curvilinear portion; 
 wherein the wire has a rigidity in torsion to allow transmission along its length of a rotational movement by a rotation of the handle, whereby the rotational movement of the wire by a rotation of the handle causes an adjustment of an opening angle of the second curvilinear portion by accumulating torque in the wire; 
 wherein the first curvilinear portion and the second curvilinear portion extend in respective planes that make an angle between them that define a dihedral angle that includes the first straight portion, wherein the dihedral angle is between 10° and 30°; 
 wherein the first curvilinear portion has a radius of curvature between 40 and 60 mm and provides an opening angle of between 70° and 110°; 
 wherein the second curvilinear portion has a radius of curvature between 10 and 15 mm, and wherein the second curvilinear opening angle is adjustable between 20° and 40°; 
 wherein the total length of the first curvilinear portion, the first straight portion, and the second curvilinear portion is between 82 and 195 mm; 
 wherein the first straight portion has a length between 30 and 70 mm; 
 wherein said distal end is configured to be positioned within an anatomical curvature of a venous system extending from a right or left cephalic vein, through a superior vena cava, and towards the septum wall; 
 wherein the distal end comprises a positioned shape when positioned within the anatomical curvature; and 
 wherein the positioned shape substantially matches the unstressed shape. 
 
     
     
       19. The stylet of  claim 18 , wherein the wire further comprises a second straight portion positioned distal of the second curvilinear portion. 
     
     
       20. The stylet of  claim 19 , wherein the second straight portion further comprises a length less than or equal to 15 mm.